Soulmate AU where you have to kiss your soulmate to find out that they're your soulmate.
Elaboration: When you kiss your soulmate, you and they will glow bright colors, so everyone around you will see that you're soulmates. People could meet their soulmates, but not know for a very long time since they would have to connect lips, and friends or acquaintances aren't exactly ones to make that happen.
EXAMPLE SHORT STORY:
TBC